[Cysteamine ophthalmic hydrogel for the treatment of ocular cystinosis]

Ocular cystinosis is a rare disease characterised by the deposit of cystine crystals on the corneal surface, which hinder patients' eyesight. Oral cysteamine is given as cysteamine; however, it does not reach the cornea due to the lack of corneal vascularization making necessary its  administration by the topical ocular route. The aim of the present study is to  determine the stability of an ophthalmic hydrogel of cysteamine, which can be  potentially prepared at hospital pharmacy departments, under different preservation conditions during a follow-up of 30 days. Different physical  and chemical parameters were evaluated: osmolality, pH and  cysteamine concentration, which has been measured by a method of ultra  performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS).  Descriptive assays were also performed, such as transparency measurement and  microbiological assays in order to verify its sterility. The obtained results  allow us to conclude that the cysteamine hydrogel is stable during 30 days,  being recommendable its preservation in refrigerated conditions.

Preclinical PET Study of Intravitreal Injections

Purpose

This work aimed at describing the time course of vitreous clearance through the use of positron emission tomography (PET) as a noninvasive tool for pharmacokinetic studies of intravitreal injection.

Methods

The pharmacokinetic profile of intravitreal injections of molecules labeled with 18Fluorine (18F) was evaluated in adult Sprague Dawley rats by using a dedicated small-animal PET/computed tomography scanner. Different conditions were studied: three molecules radiolabeled with 18F (18F-FDG, 18F-NaF, and 18F-Choline), three volumes of intravitreal injections (7, 4, and 2 μL), and absence or presence of eye inflammation (uveitis).

Results

Our results showed that there are significant pharmacokinetic differences among the radiolabeled molecules studied but not among the injected volumes. The presence or absence of uveitis was an important factor in vitreous clearance, since the elimination of the drug was clearly increased when this condition is present.

Conclusions

Intravitreal pharmacokinetic studies based on the use of dedicated PET imaging can be of potential interest as noninvasive tools in ophthalmic drug development in small animals.

Positron Emission Tomography for the Development and Characterization of Corneal Permanence of Ophthalmic Pharmaceutical Formulations

Purpose

This work is aimed at describing the utility of positron emission tomography/computed tomography (PET/CT) as a noninvasive tool for pharmacokinetic studies of biopermanence of topical ocular formulations.

Methods

The corneal biopermanence of a topical ophthalmic formulation containing gellan gum and kappa carragenan (0.82% wt/vol) labeled with 18Fluorine (18F) radiotracers (18F-FDG and 18F-NaF) was evaluated by using a dedicated small-animal PET/CT, and compared with the biopermanence of an aqueous solution labeled with the same compounds. Regions of interest (ROIs) were manually drawn on the reconstructed PET images for quantifying the radioactivity concentration in the eye. The biopermanence of the formulations was determined by measuring the radioactivity concentration at different times after topical application. Additionally, cellular and ex vivo safety assays were performed to assess the safety of the performed procedures.

Results

Differences were observed in the ocular pharmacokinetics of the two formulations. After 1.5 hours of contact, 90% of the hydrogel remained in the ocular surface, while only 69% of the control solution remained. Furthermore, it was observed that flickering had a very important role in the approach of the trial. The application of 18F-FDG in the eye was neither irritating nor cytotoxic for human corneal epithelial cells.

Conclusions

The use of small-animal PET and 18F radiotracers in ocular pharmacokinetics of ophthalmic formulations is feasible and could be a safe method for future ocular pharmacokinetic studies in humans.

Evaluation of the in vitro ocular toxicity of the fortified antibiotic eye drops prepared at the Hospital Pharmacy Departments

The use of parenteral antibiotic eye drop formulations with non-marketed compositions or concentrations, commonly called fortified antibiotic eye drops, is a common practice in Ophthalmology in the hospital setting. The aim of this study was to evaluate the in vitro ocular toxicity of the main fortified antibiotic eye drops prepared in the Hospital Pharmacy Departments. We have conducted an in vitro experimental study in order to test the toxicity of gentamicin, amikacin, cefazolin, ceftazidime, vancomycin, colistimethate sodium and imipenem-cilastatin eye drops; their cytotoxicity and acute tissue irritation have been evaluated. Cell-based assays were performed on human stromal keratocytes, using a cell-based impedance biosensor system [xCELLigence Real-Time System Cell Analyzer (RTCA)], and the Hen's Egg Test for the ocular irritation tests. All the eye drops, except for vancomycin and imipenem, have shown a cytotoxic effect dependent on concentration and time; higher concentrations and longer exposure times will cause a steeper decline in the population of stromal keratocytes. Vancomycin showed a major initial cytotoxic effect, which was reverted over time; and imipenem appeared as a non-toxic compound for stromal cells. The eye drops with the highest irritating effect on the ocular surface were gentamicin and vancomycin. Those antibiotic eye drops prepared at the Hospital Pharmacy Departments included in this study were considered as compounds potentially cytotoxic for the ocular surface; this toxicity was dependent on the concentration used.

Ocular safety comparison of non-steroidal anti-inflammatory eye drops used in pseudophakic cystoid macular edema prevention

Non-steroidal anti-inflammatory drug (NSAID) eye drops are widely used to treat ocular inflammatory conditions related to ophthalmic surgical procedures, such as pseudophakic cystoid macular edema, and they have been used for off-label treatments. The most commonly used NSAIDs are diclofenac and ketorolac and the new molecules bromfenac and nepafenac have also been used. We used primary human keratocytes in cell culture in combination with a novel technology that evaluates dynamic real-time cytotoxicity through impedance analysis. This study also included classic cell viability tests (WST-1(®) and AlamarBlue(®)), wound healing assay, Hen's Egg Test and an ex vivo histopathological assay. NSAIDs were shown to have important cytotoxicities and to retard the healing response. Furthermore, the new eye drops containing bromfenac and nepafenac were more cytotoxic than the more classical eye drops. Nevertheless, no immuno-histochemical changes or acute irritation processes were observed after the administration of any eye drops tested. Due to cytotoxicity and the total absence of discomfort and observable injuries after the administration of these drugs, significant corneal alterations, such as corneal melts, can develop without any previous warning signs of toxicity.

Chitosan and Kappa-Carrageenan Vaginal Acyclovir Formulations for Prevention of Genital Herpes. In Vitro and Ex Vivo Evaluation

Vaginal formulations for the prevention of sexually transmitted infections are currently gaining importance in drug development. Polysaccharides, such as chitosan and carrageenan, which have good binding capacity with mucosal tissues, are now included in vaginal delivery systems. Marine polymer-based vaginal mucoadhesive solid formulations have been developed for the controlled release of acyclovir, which may prevent the sexual transmission of the herpes simplex virus. Drug release studies were carried out in two media: simulated vaginal fluid and simulated vaginal fluid/simulated seminal fluid mixture. The bioadhesive capacity and permanence time of the bioadhesion, the prepared compacts, and compacted granules were determined ex vivo using bovine vaginal mucosa as substrate. Swelling processes were quantified to confirm the release data. Biocompatibility was evaluated through in vitro cellular toxicity assays, and the results showed that acyclovir and the rest of the materials had no cytotoxicity at the maximum concentration tested. The mixture of hydroxyl-propyl-methyl-cellulose with chitosan- or kappa-carrageenan-originated mucoadhesive systems that presented a complete and sustained release of acyclovir for a period of 8–9 days in both media. Swelling data revealed the formation of optimal mixed chitosan/hydroxyl-propyl-methyl-cellulose gels which could be appropriated for the prevention of sexual transmission of HSV.

In vitro and in vivo ocular safety and eye surface permanence determination by direct and Magnetic Resonance Imaging of ion-sensitive hydrogels based on gellan gum and kappa-carrageenan

Gellan gum, kappa-carrageenan and alginates are natural polysaccharides able to interact with different cations that can be used to elaborate ion-activated in situ gelling systems for different uses. The interaction between fluid solutions of these polysaccharides and cations presents into the tear made these biopolymers very interesting to elaborate ophthalmic drug delivery systems. The main purpose of this study is to evaluate the ability of mixtures of these polymers to obtain ion-activated ophthalmic in situ gelling systems with optimal properties for ocular use. To achieve this purpose different proportion of the biopolymers were analyzed using a mixture experimental design evaluating their transparency, mechanical properties and bioadhesion in the absence and presence of simulated tear fluid. Tear induces a rapid sol-to-gel phase transition in the mixtures forming a consistent hydrogel. The solution composed by 80% of gellan gum and 20% kappa-carrageenan showed the best mechanical and mucoadhesive properties. This mixture was evaluated for rheological behavior, microstructure, cytotoxicity, acute corneal irritancy, ex-vivo and in vivo ocular toxicity and in vivo corneal contact time using Magnetic Resonance Images (MRI) techniques. Result indicates that the system is safe at ophthalmic level and produces an extensive ocular permanence higher than 6h.

Cyclodextrin-polysaccharide-based, in situ-gelled system for ocular antifungal delivery

Fluconazole was studied with two different hydrophilic cyclodextrins (hydroxypropyl-β-cyclodextrin (HPBCD) and sulfobutyl ether-β-cyclodextrin (SBECD)) for the formation of inclusion complexes. HPBCD and SBECD showed low cell cytotoxicity in human keratocytes as assessed by the label-free xCELLigence system for real-time monitoring. The fluconazole–HPBCD complex was incorporated into an ion-sensitive ophthalmic gel composed of the natural polysaccharides gellan gum and κ-carrageenan. This system showed good bioadhesive properties and effective control of fluconazole release.

[Analysis of ocular toxicity of fluconazole and voriconazole eyedrops using HET-CAM]

PURPOSE

The objective of the study is to provide toxicological information through the HET-CAM test of Fluconazole and Voriconazole eye drops prepared commonly in Pharmacy Services for the treatment of fungal keratitis.

METHOD

Experimental Study. The ocular toxicity of topical voriconazole 10 mg/ml and fluconazole 2 mg/ml were evaluated by the hen's egg test (HET) on the chorioallantoic membrane (CAM). The effects on blood vessels were based on its behavior during 300 seconds and processes that may occur at each time, then we calculated the irritation index (is, irritation score).

RESULTS AND CONCLUSIONS

Both eye drops, voriconazol and fluconazole have been proven to be safe, since the IS that we obtained was zero for both samples and did not present significant signs of irritation. Therefore, these eyedrops are considered suitable for ocular use from a toxicological point of view.

[Micronutrient supplementation in parenteral nutrition in Spanish hospitals]

Several years ago, it was recommended not to add vitamins or oligoelements to parenteral nutrition (PN) solutions and to administer them immediately after the addition of the micronutrients to avoid their decay. Nowadays, it has been observed that with multilayer bags, ternary mixtures and sunlight protection vitamins degradation is minimal. Daily intake of micronutrients is necessary in the critically ill, malnourished or long-term PN patients. Aiming at knowing the schedules of use of micronutrients in PN in Spanish hospitals and the way PN bags are prepared regarding the factors conditioning their stability, we undertook a telephone survey to the pharmacists in charge of PN at the different hospitals. We compared the data obtained with those from other surveys performed in 2001 and 2003. Pharmacists from 97 hospitals answered the questionnaire (answer rate 88%). The hospital sizes ranged 104-1728 beds. As compared to the data form preceding years, we observed a better adequacy to the current recommendations, although there are still 30% of the hospitals that administer micronutrients on an every other day basis independent of the clinical situation of the patients. In most of the hospitals, multilayer bags are used and/or sunlight protection and ternary mixtures. According to these results showing the different criteria for administering vitamins and oligoelements in PN solutions, it seems necessary to elaborate consensus documents that adapt to the reality of the diverse practices besides promoting the performance of well-designed clinical studies establishing the requirements under special clinical situations.

[Satisfaction perceived by outpatients and pharmacy auxiliaries in a Hospital Pharmacy Department, as a method of improving quality]

OBJECTIVES

To evaluate the satisfaction of pharmacy auxiliaries, and patients attending the Outpatient Pharmacy, after the restructuring of the physical space and the process of dispensing drugs.

METHODS

Three months after the restructuring of the Area (January 2009), we gave satisfaction surveys (anonymously and voluntarily) over 2 weeks, to a sample of the 3,300 patients who came per month and another to pharmacy auxiliaries who had worked in the area. The surveys consisted of eight closed questions with a Likert-type format about the physical space and organization, dispensing process and overall satisfaction (primary endpoint). In addition, there was an open question to gather suggestions.

RESULTS

A total of 265 patients received the questionnaire (response rate 94%). The most valued aspect was the confidentiality (4.2 ± 0.7) and the worst was the waiting area (3.2 ± 1). There was a 100% response rate from the 26 pharmacy auxiliaries who received the questionnaire. The highest score was obtained by the installation of the bar-code reader (3.9 ± 0.6) and the lowest for organization of the stores (3.1 ± 1.2). They added comments about the lack of personnel, computer systems, organization of space and the lack of clarity of the prescription. The overall patient satisfaction was 4.2 ± 0.6 and that of the auxiliaries was 3.7 ± 0.7.

CONCLUSIONS

The results of patients and employees satisfaction surveys have been useful information to assess changes in the area and identify points for improvement. In most of the issues the satisfaction was greater in patients than employees. We believe it is necessary to carry out actions for improving physical space and organization.

[Is it worth knowing the characteristics of inpatient paediatric parenteral nutrition?]

OBJECTIVE

To describe the characteristics of inpatient parenteral nutrition during 2008 in a tertiary level paediatric hospital. To compare this practice with recent standards.

MATERIAL AND METHODS

Longitudinal, descriptive, and retrospective study of patients under 16 years receiving parenteral nutrition in 2008. Demographic data as well as data of the nutritional support were recorded.

RESULTS

A total of 120 children received parenteral nutrition, of whom 63 were under 2 years, 30 between 3 and 7 years, and 27 older than 7 years. They accounted for 1.6% of all the inpatients during that period. Most frequent indication was gastrointestinal surgery (35.5%), followed by non-surgical gastrointestinal diseases (19.8%). The average composition in the first day of parenteral nutrition was: 63.1kcal/kg (SD: 21.3); volume, 76.6ml/kg (SD: 28.4); carbohydrates 9.6g/kg/d (SD: 3.2); amino acids 2.1g/kg/d (SD: 0.6), and lipids 1.9g/kg/d (SD: 1). The mean duration of parenteral support was 10.5 days (SD: 9.8). Internal jugular vein (34.7%) and femoral vein were the most common intravenous access. The main reason to discontinue parenteral nutrition was transition to oral/enteral feedings. The complication rate was 27.3%.

CONCLUSIONS

There is an interest in evaluating standard practice in parenteral nutrition in order to develop improvement strategies. Infants and toddlers are the principal candidates for parenteral nutrition. Standardisation is one way to decrease errors in its preparation and prescription.